JPH0321935Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a hopper for mixing flats and granular raw materials, which are recycled raw materials generated when manufacturing strips such as plastic sheets and films.

(Prior Art) When a plastic film or sheet is molded, the following off-product products are generated.

Edge sheet or film on both sides of the product (usually referred to as edges), which are called unstretched areas or areas with poor thickness that occur during operation.

Slit loss products such as non-standard width products and uneven thickness products that occur when cutting with a sliver.

Non-product items that are not applicable to products and occur during unsteady conditions at the start of operation.

Broken film or sheet during operation.

These so-called films or sheets that are not included in products are generally reused.
A relatively thick sheet or film is cut into flat plates with long sides of about 6 to 8 mm using a crusher such as a crusher. This is commonly called flats.
Furthermore, when very thin films are cut by the crusher or the like, their bulk density is low and this causes trouble during transportation, so they are often turned into pellets. This pelletization is obtained by melting recycled plastic and cutting the melt in water or in the air, and it is made into rod-shaped (3 mmφ
3mm), granular (3mmφ sphere) or plate (3mm x 4mm)
is made in the shape of

Among these, the pulverized plastic raw material for recycling (hereinafter referred to as recycled pulverized raw material) is sent into the hopper main body by air transport (pressure transport or suction). The plastic raw material or new granular plastic raw material (hereinafter referred to as granular raw material) that has been pelletized and recycled as a granular product is air-fed (pressure-fed or suctioned) to the hopper on a conveyance line separate from the recycled pulverized raw material. Sent into the main body. The recycled pulverized raw material and the granular raw material are mixed within the hopper body.

Representative examples of conventional mixing systems are shown in FIGS. 2 and 3.

First, the structure of the conventional hopper shown in FIG. 2 will be explained. Reference numeral 1 indicates the hopper body, and the hopper body 1 is composed of a cylindrical part followed by an inverted conical part,
It is for storing, mixing and supplying granular and regrind raw materials. An agitator 2 is installed inside the hopper body 1, and the agitator 2 has a spiral blade provided on a shaft rotatably supported by a bearing 11, and is rotationally driven by a drive motor 4 via a reducer 5. The granular raw material and the regenerated pulverized raw material are stirred and mixed, and then supplied to an extruder (not shown) in the direction of arrow A.

A level meter 3 is placed on the desired part of the inner wall of the hopper body 1.
is installed. The same level total 3 is Hoppa main body 1
There are paddle (blade) type, electrostatic type, and other types of devices that detect the amount of raw material stored in the tank and control the amount stored.

In addition, each input port 10, 1 for the recycled pulverized raw material 8 and the granular raw material 9 is provided at a desired location on the upper wall circumferential surface of the hopper main body 1.
2 are provided, and respective input ports 10 and 12 are connected to cyclones 6 and 7, and regenerated pulverized raw materials 8 and granular raw materials are air-fed (pneumatically fed or sucked) from a film crusher and a pellet manufacturing device (not shown), respectively. 9 passes through the respective cyclones 6, 7 to each input port 10,
12 and are dropped into the hopper main body 1.

In the system shown in FIG. 2, a separate input port 1
The regenerated pulverized raw material 8 and the granular raw material 9 introduced from 0 and 12 are stirred and mixed by the rotating agitator 2, and are supplied to an extruder (not shown) as shown by arrow A.

The system shown in Fig. 3 is a hopper 13 for regenerated pulverized raw materials.
A granular raw material hopper 14 is provided concentrically outside the hopper 13, and an agitator 2
Since only the regenerated pulverized raw material 8 is subjected to the action of the regenerated pulverized raw material 8, the regenerated pulverized raw material 8 and the granular raw material 9 are stirred and mixed at the lower part of the regenerated pulverized raw material hopper 13. It is supplied to the extruder.

By the way, in the case of the mixing hopper shown in Fig. 2, the bulk density of the re-pulverized raw material is smaller than that of the granular raw material (usually about 1/3 to 1/10), so the shape of the agitator blades is No matter how much effort is made, it is difficult to mix evenly, and the extruder tends to fluctuate in discharge, which ultimately results in uneven product thickness, which lowers the value of the product or causes it to become a non-product. It was hot.

On the other hand, the mixing hopper shown in FIG. 3 is designed to solve the above-mentioned problem by separately providing dedicated hoppers 13 and 14 for the recycled pulverized raw material and granular raw material, with their centers concentrically arranged, and the recycled hopper has a low bulk density. Only the pulverized raw material is agitated using the agitator 2, and both are mixed at the bottom of the hopper 13 for recycled pulverized raw material and supplied to the extruder, but the structure of both hoppers 13 and 14 is complicated. However, there are other problems, such as high cost and time-consuming cleaning inside each hopper.

(Problems to be solved by the invention) As described above, in the conventional mixing hopper of this kind, the recycled pulverized raw material and the granular raw material are not mixed evenly,
There have been problems such as discharge fluctuations occurring or even when mixing and discharging are successful, the structure is complex and handling and maintenance are not easy.

The present invention was devised to solve these problems, and aims to provide a mixing hopper which is simple in structure, easy to handle and maintain, and which can mix evenly and has little variation in discharge. That is.

(Means for solving the problem) For this reason, the present invention separately supplies raw materials for recycling and granular raw materials obtained by pulverizing strips that are outside the product and are generated during the molding of strips such as plastic films and sheets. In a mixing hopper equipped with an input port and an agitator for stirring and mixing both raw materials, the input port for the pulverized raw material for recycling having a small bulk density is placed at the top of the mixing hopper body, and the input port for the granular raw material is placed at the top of the mixing hopper body. Each is provided in the lower inverted conical part of the hopper body,
The above-mentioned problems are attempted to be solved by stirring and mixing both raw materials at the lower part of the mixing hopper body.

(Operation) The regenerated pulverized raw material obtained by pulverizing the strip is introduced into the same mixing hopper from the upper part, and the granular raw material is introduced into the same mixing hopper from the lower side, and both are mixed by the action of the agitator at the lower part and then supplied to the extruder.

(Example) Hereinafter, an example of the present invention will be described based on FIG. 1.

In addition, in this figure, the parts with the same reference numerals as those in the conventional mixing hopper shown in FIGS. 2 and 3 refer to the same parts in this embodiment, so the differences from the conventional mixing hopper will be explained below. I will mainly explain the points.

In the figure, reference numeral 20 denotes a granular raw material input port, which is provided at an angle to an inverted conical portion 21 of the hopper body, and actively supplies the granular raw material 9 toward the lower part of the conical portion.

Here, the input port 10 for the regenerated pulverized raw material 8 is provided at the upper peripheral edge of the hopper main body 1, similar to the conventional hopper shown in FIG.

Further, the agitator 22 is also similar to the one shown in FIG. A bar 22a is provided along the conical surface of the hopper body 1 in order to provide stirring action. What is shown here is an example, and other suitable structures are of course possible.

The regenerated pulverized raw material 8 is agitated by the agitator 22 and supplied to the lower part of the hopper main body 1, and the granular raw material 9 is inputted from the granular raw material input port 20.
Thoroughly stir and knead.

Next, the operation will be described. Regenerated pulverized raw material 8, which has been air-fed from a not-shown pulverizer as shown by arrow B, is fed into the hopper body 1 via the cyclone 6. Here, the mixing ratio of the pulverized raw material 8 can be freely changed by controlling the rotation speed of the agitator 22.

On the other hand, from the pellet manufacturing device (not shown)
The granular raw material 9 that has been air-fed like this is transferred to the cyclone 7.
The granular raw material is separated from air through the granular raw material input port 20 and is input into the lower part of the agitator 22.

The regenerated pulverized raw material 8 is guided to the lower part of the hopper body 1 while being stirred by the agitator 22, and is thoroughly stirred and kneaded together with the granular raw material 9 from the granular raw material input port 20, and then supplied to an extruder (not shown).

(Effects of the invention) As explained above in detail, according to the invention, granular raw materials and pulverized raw materials are mixed with a single mixing hopper,
Not only is it possible to mix and feed evenly, producing high-quality products, but the structure of the hopper body is simplified, so cleaning work and other maintenance inside the hopper can be carried out efficiently. It is.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a mixing hopper showing an embodiment of the present invention, FIG. 2 is a cross-sectional view of an example of a conventional mixing hopper, and FIG. 3 is a cross-sectional view of another conventional mixing hopper. Explanation of the main parts of the figure, 1... hopper body, 8...
...Regenerated pulverized raw material, 9... Granular (plastic) raw material, 10... Regenerated pulverized raw material inlet, 20... Granular raw material inlet, 21... Inverted conical part, 22... Agitator.

Claims (1)

[Scope of utility model registration request] For mixing, equipped with an input port for separately supplying raw materials for recycling and granular raw materials, which are obtained by pulverizing the strips that are generated when forming strips of plastic film and sheets, etc., that are outside of the product, and an agitator that stirs and mixes both raw materials. In the hopper, an input port for the pulverized raw material for recycling having a small bulk density is provided in the upper part of the mixing hopper body, and an input port for the granular material is provided in the lower inverted conical part of the mixing hopper body, and both raw materials are fed into the mixing hopper. A mixing hopper characterized by stirring and mixing at the bottom of the main body.